共查询到19条相似文献,搜索用时 156 毫秒
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B样条正交小波的构造 总被引:2,自引:0,他引:2
基于Mallat多尺度分析理论,用Daubechies的正交小波构造方法,构造出任意阶基数B样条规范小波,并给出了相应的小波函数,尺度函数,正交象波器H和G的时频响应表达式,这类小波产生的小波基适用于一维和二维信号分解与重建过程中的Mallat快速算法。 相似文献
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讨论三元双正交小波滤波器构造的矩阵扩充问题.运用多小波提升思想与矩阵多相分解方法,给出了由插值尺度函数构造三元双正交小波滤波器一般公式.刻画了三元双正交小波包的性质,得到了2个双正交公式. 相似文献
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将2尺度双向加细函数和双向小波的研究以及相关性质推广到m尺度.同时,给出了双向加细函数和双向小波在对称与反对称时应满足的条件.最后研究了如何利用正交尺度函数和对应的正交小波.构造正交双向小波,并给出了具体算例. 相似文献
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研究了M带正交小波的构造方法,在此基础上给出了M尺度复小波的相关理论.提出了M尺度正交对称和反对称复小波的构造算法,并以M尺度复系数Haar小波为例,给出了具体的计算实例. 相似文献
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首先讨论了多尺度分析中子空间V0的性质,在此基础上得到多尺度分析生成的多重正交小波的几个等价条件,使得H.O.K im的定理2.6成为其的一种特殊情形. 相似文献
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二维紧支撑正交多尺度函数的构造 总被引:1,自引:0,他引:1
提出了由二维单正交的尺度函数构造二维紧支撑正交的多尺度函数的构造方法,并给出相应组合系数应满足的条件.研究表明,二维正交多尺度函数可由所给二维单正交的尺度函数的线性组合而成,这种由正交的单尺度函数构造出来的多尺度函数不是惟一的,但其平移伸缩构成的空间与相应单尺度函数的平移伸缩生成的子空间相同. 相似文献
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正交双向小波包 总被引:2,自引:1,他引:1
李岚 《纺织高校基础科学学报》2009,22(3)
在引入正交双向小波的基础上,给出紧支撑正交双向小波包的定义及其构造方法.讨论了这类正交双向小波包的性质.正交双向小波包是正交小波包的推广. 相似文献
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本文通过构造自适应正交小波识别混合特征畸变织物疵点。首先确定所设计小波的优化目标,然后采用二通道方法准确重建正交滤波器(Quadrature Mirror Filter, QMF)的结构实现方式,推导出目标函数,并通过目标函数选择具体的优化方法,建立起优化目标和QMF系数间的函数关系;最后采用构造出的自适应正交小波对3种类型的混合特征畸变疵点进行识别,通过两层离散小波分解,验证该方法的可行性。 相似文献
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研究三维双正交小波包的性质,推广了一元双正交小波包的概念,引入了三维不可分双正交小波包的定义并给出一种构造方法.使用分离变量法与时频分析方法讨论了三维不可分双正交小波包的性质,得到3个双正交性公式.由三维双正交小波包可以构造L2(R3)的R iesz基. 相似文献
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在油气勘探中,三维地震资料得到了广泛应用,在地震资料中具有丰富的信息,具有不同频率的信息,如何有效地提取这些信息对地层评价至关重要。连续小波变换计算量大,不便于投入实用,文章将离散小波算法引入地震资料的多尺度分析中,从地震资料中提取出不同尺度的信息可以用来分析参考。 相似文献
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Gerard Downey Paul Robert Dominique Bertrand Marie Franoise Devaux 《Journal of the science of food and agriculture》1987,40(3):219-232
Most of the observed variation between n.i.r. spectra in any sample collection is due to particle size variation; in addition, absorbance readings are highly inter-correlated. Application of multiple linear regression techniques to such spectral data produces a multiplicity of solutions which vary in the wavelengths selected and in predictive accuracy. Evaluation of all or most of these calibrations requires a significant amount of time. In the present study, alternative data treatment methods are described which reduce the effect of particle size variations, select only those wavelengths which contain significant information, and overcome the problem of inter-correlation by means of principal component analysis. These methods were applied to the analysis of dried silage for crude protein (CP) and in vitro dry matter digestibility (IVDMD); accuracy of the novel data treatments (best standard error of prediction of CP and IVDMD equal to 0.63 and 2.7, respectively) was better than that generally achieved by more conventional statistical techniques. 相似文献
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首先提出了一种新的GHM多小波预滤波方法;其次,针对多小波变换改进了常用的SPIHT量化方法.最后通过实验证明使用新的预滤波方法进行多小波变换有较高的低通能量百分比,并且在图像压缩中使用新的预滤波方法和改进的量化方法会有好的效果. 相似文献
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通过线密度预测纱线直径的方法是目前最为认可的表述之一,正在广泛使用。这一表述采用1.1为通用比容,而非1.1g/cm~3的纱线密度,提出用另一种相关理论模型计算纱线直径,也提出了纱线细度和长丝直径间关系的理论。线密度表述中,采用了预定的固定比容,因此该方法仅限用于英支支数的棉纱;通用比容模型只可在纤维密度(ρfiber)与纱线密度(ρyarn)一致的情况下使用。有关长丝的理论,采用了预定的密度和线密度(D),直径预测被限用于芳纶长丝和黏胶人造丝中。以上提到的各种理论都可在进一步的研究中用于修正和完善现有理论,旨在减轻目前工作的局限性。因此目前已经对有关常用经验公式进行了修正,以根据纱线密度和支数预测纱线直径;在现有的线密度(D)和直径(μm)关系中,提出可不考虑任何密度和原料的因素。统计关系也经检验和报道,检验分析结果显示了便于正确应用的更细微的细节。 相似文献
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Multidrug-resistant Salmonella Typhimurium U288 is a significant pathogen of pigs, accounting for over half of all outbreaks on UK pig production premises. The potential of this serovar, and other salmonellae, to enter the food chain during the slaughtering process requires that efforts be made to reduce the prevalence of these bacteria at both the pre- and post-harvest stages of production. A bacteriophage cocktail (PC1) capable of lysing various Salmonella enterica serovars was designed using the broad host-range phage Felix 01, and three phages isolated from sewage. PC1 applied to pig skin experimentally-contaminated with U288 achieved significant reductions (P < 0.05) in Salmonella counts when stored at 4 °C over 96 h. Reductions of > 1 log10 unit were observed when the ratio of phage applied was in excess of the bacterial concentration. The treatment was found to be effective at a multiplicity of infection (MOI) of 10 or above, with no significant reductions taking place when the MOI was less than 10. Under these conditions U288 counts of log10 4.1-4.3 CFU were reduced to undetectable levels following the application of PC1 to pig skin (> 99% reduction). These data suggest phage cocktails could be employed post-slaughter as a means to reduce Salmonella contamination of pig carcasses. 相似文献
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Ramamurthi Jambunathan S. Madhusudana Raju Shubhada P. Barde 《Journal of the science of food and agriculture》1985,36(3):162-166
One hundred groundnut germplasm accessions were analysed for their oil content by the standard Soxhlet extraction procedure using petroleum ether: the results were compared using functional analysis with those obtained with a commercial nuclear magnetic resonance (n.m.r.) spectrometer. On another 78 experimental samples, oil content was first obtained using the n.m.r. method and the Soxhlet values were predicted using the above functional relationship. On the 78 samples the predicted values were highly correlated (r=0.972) with those obtained by Soxhlet extraction. The n.m.r. method is rapid, easy, acurate and non-destructive. 相似文献
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本文讨论了一类线性算子的本征值相应的投影算于的特性,给出了这类线性算子的本征向量空间与投影空间之间的关系及其维数特性。 相似文献